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S1E1 - The Great Fluid Debate
255 Plays9 months ago
This month on the Random Anesthesia Topic podcast, we dive into the essential topic of fluid boluses for treating hypotension. Join our trio of veterinary anesthesiologists as we explore the nuances of fluid therapy, share our personal experiences, and debunk some common myths. Whether you’re a seasoned vet or a curious pet owner, you’ll gain valuable insights into why fluid management is critical in anesthesia. Tune in for a blend of education and entertainment that will leave you informed and inspired!
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Transcript
Introduction to the Podcast
00:00:01
vetgb89
welcome everybody to the first episode of the Random Anesthesia topic podcast.
00:00:09
vetgb89
We have Dr. Anathasha Berthel. She's chief medical officer at King Elmo Hospital in King City, Ontario. And then we have Dr. Ryan Bailey, which is the anesthesiologist at the premier veterinary group in Chicago.
00:00:28
vetgb89
Awesome. and the Anesthesiologists here at Oklahoma State, and I also own a consulting company called Sixpack Anesthesia.
00:00:39
vetgb89
I'm probably the southernmost of the three of us. Actually, here it's super warm, super healthy, so it's crazy.
00:00:48
Annatasha
Oh no, it's like 90 degrees up here. Like, don't let Canada fool you.
00:00:51
Ryan Bailey
90 degrees Celsius?
00:00:52
vetgb89
this
00:00:53
Annatasha
No, obviously I'd be dead. um I was translating into Fahrenheit for the benefit of you two.
00:00:58
Ryan Bailey
What's that?
00:01:00
vetgb89
I just sell this. I've been selling this my whole life.
00:01:02
Annatasha
I was just trying to relate to the American audience, but if you want to, it was 38 degrees Celsius, which is hot.
00:01:08
vetgb89
There you go. You know what they have to do? I have my phone in Fahrenheit and my Apple watch and sell this so that when I call my dad in the morning or my mom, I can actually tell them the temperature.
00:01:22
Annatasha
Yeah, America, like you guys need to just get on the metric ship. like Just stop being so difficult. it's really it's ah ah I'm over it. I'm tired of having to convert like blood values and like all that kind of blood glucose.
00:01:33
Annatasha
like No, no.
00:01:35
Ryan Bailey
Yeah, it's really annoying. It's like genuinely the worst. I i will also say I have made that Celsius joke like more times than like, I think it's so funny. It's like one of my favorite jokes.
00:01:48
Annatasha
Um, Um, I mean, it is funny, which I think says a lot about anesthesiologists in general.
00:01:55
Ryan Bailey
For the record, it was 115 with the heat index here today.
00:01:55
vetgb89
100%. 100%.
00:02:02
Annatasha
Oh God.
00:02:02
Ryan Bailey
Time.
00:02:03
Annatasha
Yeah. Even in Celsius, that's sweaty.
00:02:04
vetgb89
Holy cow.
00:02:05
Annatasha
Like, whoo.
00:02:09
vetgb89
I didn't think that Chicago was getting that hot.
00:02:12
Ryan Bailey
Yeah, it's really hot.
00:02:13
vetgb89
That's crazy.
00:02:13
Ryan Bailey
It's all the corn sweat, apparently, just in case you were wondering. There's a lot of corn sweat information going out there.
00:02:16
Annatasha
Excuse me?
00:02:19
Ryan Bailey
Corn, when it like matures or something, it produces humidity. And so we're in like a really corn sweat heavy situation. So the humidity is thick.
00:02:29
Annatasha
Are these actual words that just came from your mouth like corned sweat?
00:02:30
vetgb89
Wow.
00:02:32
Ryan Bailey
Yeah. Yeah, you can look it up.
00:02:34
Annatasha
No, I believe you. That's the sad part.
00:02:37
Ryan Bailey
Yeah. It's worse in champagne, for the record.
00:02:43
Annatasha
Oh, okay.
00:02:43
vetgb89
Wow.
00:02:44
Ryan Bailey
Yeah.
00:02:45
vetgb89
That's nuts.
00:02:45
Annatasha
Hmm. I just thought Chicago was toasty cause it's like a concrete jungle, but I didn't realize you had to factor in this whole sweat of the corn situation.
00:02:47
Ryan Bailey
Yeah.
00:02:54
Ryan Bailey
Yep.
00:02:56
Annatasha
Wow.
00:02:56
vetgb89
That's nuts. I knew that New York was crazy hot.
00:02:58
Annatasha
you Every day.
00:03:01
vetgb89
New York is crazy hot because of the AC, apparently, right?
00:03:01
Annatasha
Yeah.
00:03:04
vetgb89
So all the massive buildings have these ginormous AC systems, and they actually make the outside temperature one Celsius degree hotter than it should be just because of all the ACs.
00:03:18
Annatasha
What are you guys doing in your free time like researching thermal climes?
00:03:18
vetgb89
So that's...
00:03:22
Annatasha
What is going on here?
00:03:26
Annatasha
Why do you know this about like um ah New York air conditioning and porn sweating? I don't know any of this. And PS, I don't care.
00:03:36
Ryan Bailey
You've got better things to make, apparently.
00:03:37
vetgb89
I guess it's exactly, you traveled so much the, you know, within that time.
00:03:43
Annatasha
Yeah, I'm on a break. I'm exhausted. Yeah, it's time to just hang out with the cat at home. Like I'm on my traveling break. I've, you know what, I've contributed to global warming through my carbon footprint and now I'm playing it down. So don't nod Bailey.
00:03:59
Annatasha
Don't nod.
00:04:00
vetgb89
That's awesome.
00:04:00
Annatasha
I'm not the place that has corn sweat issues. Okay. So don't even like, don't even try it.
00:04:07
vetgb89
That's awesome. So I guess the the question I have for you guys is Anastasia related just to
Answering Anesthesia Questions
00:04:15
Annatasha
The surprise question, I just want everyone on the podcast to know that we have not been briefed. So this is like a surprise exam for us.
00:04:15
vetgb89
go.
00:04:22
vetgb89
Yeah, so every every episode we're going to pick a random question and Actually, it's truly random. So I have actually three envelopes and I just got, and there's just big blend right before we started.
00:04:35
Ryan Bailey
Oh, wow. It's so official.
00:04:37
vetgb89
That was like...
00:04:37
Annatasha
it's like It's like cards for humanity, but not funny and maybe not fun. totally related, yeah.
00:04:42
vetgb89
Probably not.
00:04:44
Annatasha
Okay.
00:04:44
Ryan Bailey
In some way, it feels like doing oral boards, but like both more and less intimidating because it's being recorded. At least no one was recording me make an ass of myself in oral boards.
00:04:56
Ryan Bailey
So that was good.
00:04:58
Annatasha
glad I'm glad I'm the only one who walked out of that feeling really stupid.
Comparing Human and Veterinary Medicine
00:05:03
vetgb89
I guess the question I have for you today is... So you know a lot of practitioners out there, the very first thing they do as soon as they see some hypotensive patient is to give a fluid bonus.
00:05:24
Annatasha
but just Let's just rip that can of worms right open from the first question. like yeah
00:05:28
vetgb89
Right. Yeah. I know it's loaded.
00:05:32
Annatasha
yeah
00:05:34
vetgb89
It's loaded. but What's your thought on
00:05:40
Annatasha
I'm going to let Bailey rock on this one first.
00:05:42
Ryan Bailey
So this is let me let me jump in real fast on it can and like totally derail the conversation before we even start. But I was reading there's an anesthesiology humans focused subreddit that I have discovered and it is like truly brings me such joy so often. But today's topic there was a discussion topic on the use of fluid therapy in septic patients and bolusing versus like processors and obviously it's this very specific subset of patients so like not applying to this patient that we're discussing here but
00:06:05
vetgb89
that?
00:06:18
Ryan Bailey
just so much of the conversation their conversation is focused on not just the like subjective slash objective measurements that we do have access to in a non-invasive way, but so much more focused on invasive and like semi-invasive measurements like TEE and like Doppler measurements through like an esophageal probe.
00:06:43
Ryan Bailey
placement type device that like we aren't even using in academics routinely. And also discussing like using targeted variables like you know like central venous pressure and like like ah like other markers that we're not routinely monitoring in our veterinary patients because of complications and just like we're basically decades behind and like just being really sad sorry to, sorry to bring it down everyone.
00:07:16
Annatasha
Yeah, anyway, that was a great podcast.
00:07:17
vetgb89
Sad truth.
00:07:18
Annatasha
Thanks, Bailey.
00:07:19
vetgb89
Sad truth. But that's, I always tell my students, you know, they were like 24 years behind that list.
00:07:21
Ryan Bailey
Yeah.
00:07:21
Annatasha
Yes, great.
00:07:27
Ryan Bailey
Oh my God. Yeah.
00:07:27
Annatasha
Where'd you get that random number of 24?
00:07:32
Annatasha
Was it from the corn sweat?
00:07:32
vetgb89
It's a random number.
00:07:33
Annatasha
Like, what's happening? i
00:07:35
Ryan Bailey
Yeah.
00:07:35
vetgb89
It's the corners, right? Yes.
00:07:38
Annatasha
Is it Celsius? Do you start with a fluid bolus? You know what, we should just call you know what we should call this podcast, it depends. That should be because I swear to God, that's going to be my answer like 98% of the time. like they're so It's such a rare occasion where I have absolutely black and white cutoffs for things.
00:08:00
Annatasha
And I know that's never particularly helpful for people who are uncomfortable with anesthesia or who are still on a like a growth trajectory for their own learning and skill, that's like my official answer. right like you know The first question out of the gate is, am I giving a fluobolus because that patient is hypovolemic? And the next question I ask myself is, do I believe in relative hypovolemia from a state of induced vasodilation?
00:08:26
Annatasha
know, and just because you have a volume deficit does not make you a fluid responder. So I actually don't think there is a right or wrong answer here because I don't think anybody knows what the answer is. Um, Um, I mean, it's the same thing. It's not just fluid. It's the type of fluid. It's the rate that you give it. It's the total volume per like body kilo that's actually given.
00:08:53
Annatasha
It's the physiological state of the patient. So what's renal function? What's cardiac function? What's vascular status like, you know, it's it's so highly subjective both from the point of view of the clinician and from the point of view of the patient and at some point I feel like for me fluids almost has reached the point where it's like an art form like I I almost go like this gut intuition of like how much volume I think the patient needs and yeah, I'm looking at pressures and rates and and pulse pressure variations on ventilation and lactate and, you know, et cetera, et cetera. You know, what's my base excess, but you know, I get a good feeling like after one or two boluses, like if I'm looking at those parameters, you're not really improving. I'm going to switch tactics pretty fast. Like I'm going to change tack because I'd rather not volume over volume overload you and not volume volume overload in the sense of like, everyone thinks volume overload equals pulmonary edema. But for me, I'm thinking more like,
00:09:50
Annatasha
gut edema, and I'm thinking more hemodilution, which is going to send the criticalist just off off the fucking rope. But you know, like you're dropping calcium and like, you know, I mean, all those kinds of things that you get as punishment for being aggressive with fluids. So yeah, my answer is it depends. Do I think it's right or wrong? No.
00:10:12
Annatasha
think starting with a fluid bolus is reasonable in most instances yeah especially in GP where they don't have phenylephrine or noradrenaline to hand.
Fluid Administration in Clinical Scenarios
00:10:22
Annatasha
But yeah, that's that's my two cents.
00:10:24
Annatasha
well That's my two cents of veterinary anesthesia.
00:10:30
Annatasha
Maybe we should call it those two cents.
00:10:30
Ryan Bailey
I mean, i think yeah i I feel like when you're dealing with these like, you know, looking at patient population, you know, like these 95% patients that we're talking about,
00:10:34
Annatasha
Or three cents as the case may be.
00:10:51
Ryan Bailey
I don't think it like matters what you do. like You could do anything and it's probably gonna be fine. like I know it's like a terrible answer, but like in these patients who are otherwise healthy, who have very low level of comorbidities,
00:11:07
Ryan Bailey
Also because we're dealing with dogs and cats and not like smokers and drinkers, like we are so fortunate that like we can almost do whatever we want within, within reason.
00:11:20
Ryan Bailey
And because of standard deviations and bell curves, we're, it's going to be fine. And that's like a terrible set.
00:11:28
vetgb89
yeah
00:11:30
Annatasha
I mean, most of the GP, I mean, most of the GP animal population is not going to hit the table in a state of hypovolemia, right?
00:11:31
vetgb89
no
00:11:37
Ryan Bailey
Right.
00:11:37
Annatasha
Like that's usually like referral level stuff, you know, like you have patients who are in hemorrhagic, septic, cardiogenic, neurogenic shock, and you're just like, oh but bla but you know, like a routine spay who has no hemorrhage on the table, like you're, what do you volume ball, bolusing that patient for?
00:11:40
Ryan Bailey
Yeah.
00:11:51
vetgb89
Yeah.
00:11:53
Ryan Bailey
Yeah.
00:11:53
Annatasha
What is that achieving, right? And then then you think about their total anesthesia time is like 15 to 20 minutes.
00:11:55
vetgb89
Now,
00:11:59
Annatasha
So the total volume of fluids you've probably given is like 14 mils total, not even per KIG. Do we honestly think that 14 mils total has made some sort of beneficial difference?
00:12:10
Ryan Bailey
So that brings up something that came up in symposium last year.
00:12:10
Annatasha
I'm struggling.
00:12:17
Ryan Bailey
Lydia Love talked about it, but thinking about fluids as more of a total dose over time and not as like a mils per kilo per hour, essentially. And so that like, that feline neuter, that, you know, quick spay procedure in a GP, should those cases really be on 10, 20 mils per hour of fluids because they're getting so little fluid just as a function of time. And that like there are like curves in humans showing like increasing mortality with limited fluid rates, decreasing to a certain point and then increasing back up again.
00:12:54
Ryan Bailey
And so what we're looking for is this like Goldilocks situation, which I guess that could be the name of the podcast, Goldilocks in the state of Louisiana.
00:13:00
vetgb89
yeah
00:13:06
Annatasha
yeah
00:13:06
Ryan Bailey
but like thats is like
00:13:08
Annatasha
Beanie, what do you do? like What are your thoughts? like i
00:13:12
vetgb89
So, here is my thought, right? So, like, I take a lot of this info from human medicine. Unfortunately, we don't really have a good chunk of literature on this and in veterinary medicine. but What I always tell my students is, you know, LRS in a healthy patient that's normally hydrated has been shown to last from injection to when it shows up in the bladder about 20 minutes versus in a dehydrated patient has been shown to last between
00:13:50
vetgb89
70 to 80 minutes okay from injection again to when it shows up in the blender. If you're not needing that fluid, it's totally pointless. right You're losing it so fast that even if it was to make a difference in reality,
00:14:10
vetgb89
It's very, very much temporary. you know The other piece of info on this, I think, is with the new revised French Starling equation that puts your with the old glycoalyx discovery and whatnot, that that you know puts the absorption of fluids in the hands basically of solely of the lymphatic system. The lymphatic is so slow. like the the The chance of like accumulation is actually crazy high now. right and so like If the fluid gets out of the vessels really fast because you're normally hydrated and
00:14:49
vetgb89
now you're just potentially slowing the absorption so much because you're, I mean, the absorption is so slow because of the lymphatic system is the only one that now we know is the one that does that. Then, you know, the risk of overload to me is too big. And so like, my idea is if the patient is not the available, what the hell do you give the fluid balls for? Like, it doesn't make sense, right?
00:15:17
Annatasha
Yeah, I also often hear sometimes like the patient is still hypotensive and I'm like, okay, well, what have you done?
00:15:21
Annatasha
And look, I gave a bolus. How long did you give it ago? About four hours at induction. Well, to your point, like the intravascular retention of a crystalloid is negligible in in a uvolemic or a normal volemic patient.
00:15:27
vetgb89
Sure.
00:15:37
vetgb89
Yeah.
00:15:38
Annatasha
Yeah. So like I said, I think one bolus like off the cuff is probably not going to do any harm, but do I think you're going to resolve hypotension?
00:15:39
vetgb89
it's
00:15:47
Annatasha
If that is your only intervention, doubt it.
00:15:48
vetgb89
It's... No.
00:15:52
Ryan Bailey
Sure.
00:15:52
vetgb89
No.
00:15:53
Ryan Bailey
What like counterpoint again, like in the, like a more full heart beats stronger, right? Like you increase contractility by stretching the myocardium to a point.
00:16:04
Annatasha
Yeah, that's right. Right atrial fluid, rapid injections of fluids into right atrium will cause your heart rate to go up. Also, I can't believe Beanie brought up Frank Starling on the first podcast.
00:16:10
Ryan Bailey
Walk in.
00:16:14
Annatasha
Like, ah should like should we be studying? Like,
00:16:19
Annatasha
like oh, I was like, oh, we're going. I was like, we started with fluids. We talked about Frank Starling. Like, I was like, we brought humans into this. And I was like, oh, this is getting technical fast. and All right, people. Definitely bringing wine next time.
00:16:35
vetgb89
Well, next time one of you two picked the topic, so you figure it out.
00:16:38
Ryan Bailey
god
00:16:39
Annatasha
Oh, o that is that is a danger zone.
00:16:41
vetgb89
You figure it out.
00:16:44
Annatasha
Yeah, I'm in danger.
Fluid Therapy Complexity and Presentations
00:16:46
Annatasha
But yeah, ah yeah, that's I like I said, beating, I think it's so incredibly fluids are so subjective. And like I presented this last year at the European conference, and I spoke for 50 minutes.
00:16:56
Annatasha
And at the end, I made zero conclusions.
00:16:58
Ryan Bailey
Yep.
00:16:59
Annatasha
And mine was a literature review. So I basically looked at all the relevant papers in the last three to five years, both human and veterinary. And at the end, I was like, I have no answers. Take care. Like, mic drop.
00:17:12
vetgb89
That's amazing.
00:17:14
Annatasha
Yeah, I'm definitely not getting invited back.
00:17:17
Ryan Bailey
ah
00:17:22
vetgb89
Well, I mean, but that's how it is for a lot of topics, right? We really have, you know, a clear cat, black and white answer, you know, it's very like, it's very much subjective, right?
00:17:34
vetgb89
so
00:17:34
Annatasha
Well, Bailey and I have been calling it for years, fancy guessing, right? Like what we're doing is we're making skilled, educated and experience-based decisions.
00:17:38
Ryan Bailey
yeah
00:17:43
Annatasha
But at the end of the day, I cannot write out a formulaic sheet for what you should do when and be right. So I'm fancy guessing.
00:17:50
Ryan Bailey
Yeah.
00:17:50
vetgb89
Yeah.
00:17:50
Ryan Bailey
and I think also like in the hand, like the other, I don't know, to, to your question earlier, being about like for the general practitioner who has this case, like looking at it, fluids are going to be like,
00:18:05
Ryan Bailey
they're not benign, but of the options listed, they're going to be one of the most benign options that you have in, you know, variable skill levels hands, right? Like you put the wrong patient on dopamine and it's like, boom, you've got VPCs and a cat.
00:18:27
Ryan Bailey
And like, what the hell do you do? What if that progresses to like ventricular tachycardia? Like, are you going to be pushing lidocaine to that cat? Do you have other antiarrhythmics in your practice? Like dopamine's relatively safe, but there's definitely patients out there that are like, you don't want to meet them. You don't want the two of them to meet one another. And then the use of anticholinergics, like, I don't know. There's like, I think they're pretty benign, but people are,
00:18:57
Ryan Bailey
They're loads to use them for some reason. and So like fluids end up being this like default easy option.
00:19:05
Annatasha
Yeah, because I think they appear to be benign. But you know we've learned in the last five to 10 years that that's not necessarily the case. But I'm not sure that's being disseminated at the level of like junior surgery and vet school, unfortunately.
00:19:13
vetgb89
right
00:19:18
Annatasha
Also, the humans, you know they make a big palava about fluids.
00:19:18
Ryan Bailey
Yeah.
00:19:18
vetgb89
Nah.
00:19:21
Annatasha
But every time I go in for a procedure, like they basically run a liter of fluids through me in like five minutes so that I spend the entire procedure trying not to pee my pants. So they obviously don't care all.
00:19:31
Ryan Bailey
him
00:19:31
Annatasha
like
00:19:31
Ryan Bailey
daily lamp
00:19:32
Annatasha
like Like, yeah, they're, they're yeah like as I'm heckling them about my myself sedation protocol.
00:19:33
vetgb89
We really just hate you.
00:19:41
Ryan Bailey
but
00:19:41
Annatasha
But yeah, I ah like like I've, they're not judicious with fluids like an yeah ER if you're presenting for migraines or what have you, like they just slam it into you and it's cold.
00:19:50
Annatasha
And it makes you wee. And you know, yeah, I've never found them to be particularly motivated about that in any particular capacity.
00:19:53
vetgb89
Yeah.
00:19:56
Ryan Bailey
And I assume it's a billion, right?
00:19:58
Annatasha
So
00:19:59
vetgb89
Yeah. No, I mean, it seems like in humans they don't care for, you know, they're very long. They have a lot of nonchalance, you know, with a lot of things, you know.
00:20:09
Annatasha
But they also run dry anesthesia, right?
00:20:09
vetgb89
i i Yeah.
00:20:11
Annatasha
Like that's an actual technique to run dry anesthesia. And like from my point of view too, like I don't put a neuter that I know is going to take three to four minutes. I'm not going to spike a bag of fluids.
00:20:22
Annatasha
That's wasteful. And I don't think it's beneficial to the patient. And if anything, it's just going to end up floating in the Pacific Ocean on Garbage Island. So why am I incurring that cost and wasting time and polluting the environment to give?
00:20:36
Annatasha
like oh I could just push flush if I wanted to. Like, oh, this cat needs a bowl.
00:20:39
Ryan Bailey
Mm hmm.
00:20:40
vetgb89
Yeah.
00:20:40
Annatasha
I'll just push flush.
00:20:41
Ryan Bailey
Yeah.
00:20:41
Annatasha
Right? Like, there's no point. So it's no point.
00:20:44
vetgb89
Yeah, no, that's fair. I mean, the only damage...
00:20:49
vetgb89
The only damage we really see with like, you know, people coming back to the idea of like fluids being benign, right?
00:20:49
Ryan Bailey
Yeah.
00:20:55
vetgb89
So fluids, I think they are benign. I mean, they could be the most benign of the options, as you as you say, like the least dangerous, right? More than benign, I think, the least dangerous.
00:21:02
Ryan Bailey
yeah yeah
00:21:04
vetgb89
But in reality, I think what makes it
00:21:05
Ryan Bailey
Yeah.
00:21:10
vetgb89
quote unquote, dangerous from my side is that, you know, there are studies at least in humans that show that, you know, if you have hypotension for less than, you know, 60 millimeters of mercury of minute to your pressure for 11 to 20 minutes,
00:21:28
vetgb89
you double your chances of getting ADI, right?
00:21:31
Ryan Bailey
Mm hmm.
00:21:31
vetgb89
And if you go below 55 for like 20 minutes, you actually almost triple your chances of getting ADI. And if it's below 55 for more than 20 minutes, it's actually, you have 3.8 times chances of getting ADI, compared to normal patient.
00:21:50
vetgb89
Now, I don't know how this, I mean, I think nobody knows how this translates to our patients, right? But it's a study done in humans, of course, like 60 plus thousand humans. But, you know, to the point is that, you know, if you're delaying the actual real answer to that type of tension, then that's what, to me, it becomes dangerous, right? It's not just another of like, oh, this is, it's probably not gonna hurt, but it does because you're wasting time on it, right? Potentially. So, I don't know, I think, to me, when somebody asked me about the group or some like, okay, what's PCCT be, right? Like, if the vision is not the agreement, don't waste 10 minutes on it. It's a waste of time.
00:22:38
Annatasha
Yeah, and I think if you have if those kind of numbers are being churned out for people, then I would imagine that risk is higher in cats because of their different kidney anatomy and them being desert species.
00:22:38
vetgb89
All right, but.
00:22:51
Annatasha
So that's concerning. But i personally, I think one of the most benign interventions you can do is turn down the isoflurin. right? Like turn down the inhalant, right?
00:22:58
vetgb89
yeah
00:22:59
Annatasha
Like that's the most benign thing to do take away the root of the evil, right? Like, I mean, almost everything then, you know, sort of basic anesthesia is going to be dose dependent related to your inhalation agent.
00:23:10
Annatasha
And the most benign thing to do is try and, you know, turn that down, but keep them at the steady plane by using some injectable that, for example, has less cardiovascular interference, you know what I mean?
00:23:22
Annatasha
So yeah, i I mean, I'm always one like I'm always like, okay, well, as you know, what's the depth like? I mean, cats are trickier because they'll be like crashing from hypotension and like awake. But dogs, you know, like usually ah if they're hypotensive, they're at a they're usually at a deep plane.
00:23:37
Annatasha
So that that to me is usually step one is can I can I do something that's max bearing to take away what's actually causing the hypotension?
00:23:37
Ryan Bailey
and
00:23:46
vetgb89
yeah No, absolutely, absolutely. And to that point, you know, I always tell my students here, sometimes they're like, you know, in Europe, actually, a bunch of GPs does Tiva.
TIVA vs Inhalants in Anesthesia
00:23:58
vetgb89
They just do Tiva because it's much easier than enough to have the vaporizer service serviced every year, they don't have to worry about it.
00:23:59
Ryan Bailey
Thank you.
00:24:06
vetgb89
They just put everything on a prop before Tiva and that is it.
00:24:10
Ryan Bailey
The dream. The dream. I. Also, enough again, going back to the fucking subreddit, like the amount of Tiva people are talking about doing seem like just casual Tiva cases, like just no big deal. Put them on Tiva. And it's like we are so like loath to do like we just rely so much on fucking inhalant.
00:24:37
vetgb89
We do. That's the problem. I think people don't realize this.
00:24:41
Ryan Bailey
That was so stupid.
00:24:42
vetgb89
It's so much easier. Like, a syringe farm nowadays is like, you know, you can find them a four-a-dongle box, right? and you know, probable convert to the usage or probable convert to data nowadays is actually not that that the expense is not that different. I think we're doing a really shitty job in that schools and telling, you know, the students that he was more expensive. The reality is the the way we price the anesthesia makes it more expensive.
00:25:13
vetgb89
That's because, and usually in the packages, it does include the inalement, right?
00:25:13
Ryan Bailey
Yes.
00:25:18
vetgb89
But if you remove the inalement out of it and you have the probable CRI, in reality, the price will be very much comparable. But the way we price it makes it more expensive. It's not because the probable CRI is more expensive, you know?
00:25:33
vetgb89
It's also safer for the environment, you know, that's the other.
00:25:37
Annatasha
I also find it wild that for the most part, we're still stuck on isoflurine. You know, like, I don't understand like you'll but build a brand new hospital and buy all this new equipment and we'll still be bringing isoflurine vaporizers in like tech three isovaporizers.
00:25:41
Ryan Bailey
All right.
00:25:51
Annatasha
And I'm like, who, who, why, you know, like, what is, why is this happening? just don't understand like our married commitment to isoflurine in particular.
00:26:01
Annatasha
And also, you know, I mean, Inhalants are the devil. Like, you know, they cause almost all the problems.
00:26:08
Ryan Bailey
Mm hmm.
00:26:08
Annatasha
They make, you know, if they leak into the room, they make everyone feel crusty. know, they're bad for the ozone layer. so, uh, you know,
00:26:15
Ryan Bailey
No one really understands them at all. Like no one understands like anything about like the physics, the the lack of understanding of the physics of inhalant like uptake and delivery is just like just like I can turn your flow to two, crank that vaporizer to two and just like.
00:26:40
vetgb89
Boom.
00:26:41
Ryan Bailey
And it's like, what are we doing? Like, why are we not like so fine? We use ISO, whatever. Like, who cares? Big whoop. But like, why are we?
00:26:52
Ryan Bailey
Are there still so many places out there that don't have gas analysis? Like, what are we doing?
00:26:58
vetgb89
yeah
00:26:59
Ryan Bailey
Like, is this the dark ages? Where's the hammer?
00:27:01
Annatasha
Yes. Yes. Just getting like like expired gas analysis is like a struggle at referral hospitals still, right? Like it's because they want to understand why that that is you know worth the additional pricing on the multi-parameter monitor.
00:27:16
Annatasha
So like that's still a fight that everyone is having, but I don't think anyone understands it.
00:27:21
Ryan Bailey
I know.
00:27:21
vetgb89
Yeah.
00:27:23
Annatasha
I mean, to be fair, none of us technically understand the mechanism, right? And I'm like, oh.
00:27:28
Ryan Bailey
Yes.
00:27:28
Annatasha
Like, how does this work? And I'm like, something about a channel.
00:27:33
vetgb89
I mean, we don't really even know, right?
00:27:34
Ryan Bailey
Wait.
00:27:35
Annatasha
right.
00:27:35
vetgb89
There's 100 years later, we have no fucking clue about, like, unions actually work, right?
00:27:38
Ryan Bailey
Yep.
00:27:40
Annatasha
right
00:27:42
vetgb89
It's like,
00:27:42
Annatasha
but Like you can't ask anybody about partition coefficients because they'll start to panic and like they don't know what Meyer Overton is.
00:27:47
Ryan Bailey
Okay.
00:27:48
Annatasha
And I'm a big believer. Like you shouldn't be, you know, using stuff with false confidence when you generally don't understand what you're doing, especially when what you're doing holds a life in the balance.
00:28:01
Annatasha
But, you know, that's just my soapbox anesthesia spiel, but yeah. Yeah. Like, I mean, I'll say that, you know, I'll get people all the time, like, well, I want to learn ultrasound guided blocks.
00:28:07
vetgb89
i totally
00:28:11
Annatasha
And I'm like, well, what's the mechanism of action of propofol? And then they won't know. And then I'll be like, well, I guess we are going to learn how to walk before we fly today. Aren't we?
00:28:18
Ryan Bailey
True.
00:28:21
Annatasha
Yeah.
00:28:21
vetgb89
Absolutely. Yeah, that's, that's nuts.
00:28:26
Annatasha
Which we could not be more far off of like volume resuscitation right now. if We tried.
00:28:31
vetgb89
yeah
00:28:32
Ryan Bailey
i guess I guess that's also the thing that influences so much of what I do is like i I am very lucky. like I argued when I first started, like we need gas analysis in every monitor that we have. And I've got it in like over 50% of the monitors. Every surgical monitor has gas analysis. So I know inspired, expired ISO. So like I can walk in a room.
00:28:55
Ryan Bailey
and know essentially where that patient's at with like a glance at the monitor and then like but like knowing the protocol in my head. So if I walk in, one of the dogs at 1.7, and this is a patient that also got dexametatomidine and methadone, I'm like, All right, like I will walk over and I will immediately adjust the vaporizer and be like, all right, we're gonna have a discussion on how this is like a completely inappropriate amount of of drugs to be giving this patient because it is. And like if I walk in and the patient's 0.6 and we haven't cut the patient and we're in the midst of a fluid bowl, as I'm like, well, this doesn't look like it's going great yet. So like let's get you know let's start bringing in something else. like let's
00:29:42
Ryan Bailey
you know, step out of the room, get a quick mac reducer if it's a dog, if it's a cat, get a presser.
Non-Rebreather Systems in Veterinary Anesthesia
00:29:52
vetgb89
Let's grab that Norepinephrine.
00:29:54
Ryan Bailey
Yes, exactly.
00:29:57
vetgb89
That's awesome. That's awesome. No, but that's that's the sad truth, right? Like, you know, people see the pricing on, you know, the gas synopsis and then it's like, I mean, I think we recently got some quotes. I mean, we just bought eight new machines, and we got gas analyzers, thank God, on all of them. But, you know, the price of the gas analyzer was almost the price of the monitor.
00:30:22
Ryan Bailey
Oh yeah, yeah.
00:30:22
vetgb89
so
00:30:23
Annatasha
Yeah.
00:30:24
vetgb89
you
00:30:25
Annatasha
Well, you know, it's funny because like a GP will have one multi-parameter monitor and they won't invest in that, even though let's say they'll do five to six anesthesia a day, but they'll invest in the $30,000 like digital x-rays for dental that they do, you know, twice a day.
00:30:26
vetgb89
i
00:30:38
Annatasha
And you're like, you know, it's not going to kill you, a dental x-ray, you know, what's going to kill you is a nice flooring overdose, especially where I get phone calls all the time and GPs like
00:30:39
vetgb89
yeah
00:30:47
Annatasha
My patient's profoundly bradycardic, like he's not responding, he's super hypothermic. And I'm like, okay, well, what's your ISO at? And they're like five. And you're like, oh yeah, I think I've identified the problem.
00:30:57
Ryan Bailey
eleven
00:31:00
Annatasha
And that's not even in Celsius.
00:31:01
Ryan Bailey
which then, even worse, is when you use the worst system in the world, the bane.
00:31:02
Annatasha
Like.
00:31:11
Ryan Bailey
The bane of my existence.
00:31:14
vetgb89
I know you feel, Ryan.
00:31:15
Annatasha
I'm trying. i feel like you should pay us for that joke
00:31:17
Ryan Bailey
aye
00:31:19
Annatasha
oh
00:31:19
Ryan Bailey
I hate non-rebreathers, so dangerous, and then add lack of gas analysis to, I mean, I guess like with non-rebreather you can argue, know the concentration the patient's getting, but like, man, that is just such a rodeo.
00:31:34
Ryan Bailey
It is like playing with a loaded gun to me. Like you just don't know, like you're just adjusting that thing and it's just all, the patient's all over the place, the depth is all over the place, no thank you.
00:31:43
Annatasha
I feel like you should pay us for that joke.
00:31:45
vetgb89
It's a roller coaster.
00:31:49
vetgb89
Yeah. I mean, we still teach the students, you know, I don't, but some people still teach us with students that, you know, about seven kilograms, you can use your review system and below seven kids.
00:32:02
Annatasha
made up number, made up number.
00:32:05
Ryan Bailey
Yeah, that was back when the discs were made out of metal.
00:32:05
Annatasha
Like, like where are these five kilos, seven kilos, 10 kilos?
00:32:08
vetgb89
Right.
00:32:11
Annatasha
These are all arbitrary cuts. all Everyone listening, all three people listening to this podcast, um I just want you to know that all of these numbers.
00:32:18
Ryan Bailey
Not this thing, so it's only two.
00:32:22
Annatasha
Yeah, I was like, all of those are arbitrary cutoffs and you could actually put a hippopotamus on a bane. You just have to have the right flow rate.
00:32:28
vetgb89
Yeah.
00:32:29
Ryan Bailey
Yeah.
00:32:32
vetgb89
It's true. It's true. But you can also put your two kid cat on your breathing system. You know, just use the pediatric one, adjust your, you know, bag size accordingly.
00:32:45
vetgb89
And then that's fine. It's totally fine. Nowadays, the valves are made of like super thin plastic. They barely have any weight. You know, every single time I keep unscrewing those valves and just showing them to the students.
00:32:53
Ryan Bailey
Yeah.
00:32:58
vetgb89
I was like, you know, feel this. This is like,
00:33:01
Annatasha
Well, see, I always get the answer for, if you want to convert a small patient to a circle, is that, and this is the hill that I'm going to die on.
00:33:02
vetgb89
It's weightless.
00:33:10
Annatasha
The bane might be your bane, Bailey, but mine is, well, when you want to put something small on a circle and they say, won't it be too much dead space? And I'm just like, what?
00:33:22
vetgb89
Dying inside.
00:33:22
Annatasha
And then I launch into, like, Bailey might launch into his isoflorine overdose thing, but I launch into my, do you know what dead space is?
00:33:30
Ryan Bailey
Oh my God. Meanwhile, meanwhile, the tube but is this far out of the patient. It's like a five that's never been cut. And they're like, but want to be too expensive?
00:33:42
Ryan Bailey
And you're like, not, not one.
00:33:45
Annatasha
And then I'm like, oh my god, um that's the hill I'm going to die on is the dead space in the circle argument. And I'm just like, I don't know what to do with everybody in this community some days.
00:33:51
vetgb89
Aww,
00:33:53
Ryan Bailey
And also, like, we have monitoring. Like, let's use our brains. Like, oh, look, the inspired CO2 is elevated on my circle on this half a kilo animal. Wrong choice, Bailey. Move along.
00:34:14
Annatasha
I do think, though, that breathing circuits are one of the most, especially the non-rebreathers, are one of the most poorly understood aspects of veterinary anesthesia.
00:34:23
vetgb89
Oh, absolutely.
00:34:23
Ryan Bailey
I think it's been way less than I thought.
00:34:23
Annatasha
Especially if you point out, being like, people don't know that there's sub-classifications of the non-rebreathers, right?
00:34:29
Annatasha
Like, they think it's a bane, because they use a bane. They think it's like, ah you know, a T-piece if they use a T-piece. But they don't know about, like, A's and, and like, I'll say he uses C all the time.
00:34:39
Annatasha
It's an amu-bag, and it's like, You know, and you're, and you're just like you guys, again, like we're using stuff that, you know, can giveth life and it can taketh life right as quickly. And we don't know what we're doing.
00:34:53
vetgb89
Yeah. Yeah, absolutely. Absolutely.
00:34:56
Ryan Bailey
It's a fluid.
00:34:57
vetgb89
that's and I know how we ended up on.
00:34:58
Annatasha
Yeah.
00:34:59
Ryan Bailey
It's a fluid.
00:35:00
Annatasha
We don't know about fluids. We don't know about isoflorine. We're really getting through the list here, boys.
00:35:08
Ryan Bailey
and when you fla a little tim
00:35:10
vetgb89
I don't know how we got to the Bain system and from fluids, but yeah, that's geez.
00:35:15
Annatasha
It was the bane of Bailey's life and then somehow I got on Dead Space which just makes me want to give up.
00:35:26
vetgb89
I think that that's one of the most like poorly understood part of like, you know, what actually it is that space. And also, like, people worry about it randomly, right?
00:35:39
vetgb89
Like, I'm like, oh, but I bought about that space. I was like, well, the blood pressure is like 45, right? And I'm like, the fuck cares on the dead space?
00:35:50
vetgb89
You know what I mean?
00:35:50
Annatasha
My favorite is when the temperature is like 32.3 and you're just like, what are we doing here people?
00:35:55
Ryan Bailey
fight
00:35:57
vetgb89
And that's in some sense, it's not in very much.
00:35:57
Ryan Bailey
Oh my god.
00:36:00
Annatasha
That isn't Celsius. It would be worse if it were Fahrenheit. But yeah, no, I'm, yeah, you're right. You're right. Meaning like we're worried about this much dead space, which most patients with normal physiological parameters for and an inappropriate anesthetic depth will naturally overcome.
00:36:13
Ryan Bailey
Mm-hmm.
00:36:15
Annatasha
But you meanwhile, you know, yeah, we're family hypothermic, bradycardic and hypotensive. and
00:36:21
vetgb89
Doesn't matter.
00:36:22
Annatasha
I'm going to do a dental.
00:36:30
Annatasha
lord
00:36:30
vetgb89
The other part is like that. I mean, if you put them on a ventilator, it doesn't fucking matter, right?
00:36:35
Annatasha
Well, because paralyzed because they paralyze everything in people.
00:36:35
vetgb89
Like, you know, you can put...
00:36:37
Ryan Bailey
Once again, once again, it's like we have the tool right there to just solve all the problems. And again, human beings, you're probably going on the ventilator because you're getting paralyzed.
00:36:50
Ryan Bailey
I'm not saying they don't, but like they're using the vent all the time and they still have good outcomes than people who smoke and drink and do all these bad things to our lungs versus these pets whose like lungs are like semi indestructible, honestly.
00:36:55
vetgb89
Absolutely.
00:37:04
Annatasha
I mean, speak for your own cat, mine's a total chain smoker.
00:37:08
Ryan Bailey
yeah
00:37:12
Ryan Bailey
Okay.
00:37:13
vetgb89
so
00:37:13
Annatasha
No, that's fair, that's fair. I mean, I always, i I think I always get a little upregulated about positive pressure ventilation and like, is it causing, you know, biotrauma and like shear forces and, you know, it's physiologically, it's physiologically an abnormal state, but of course, you know like is it going to make a big deal in a 20 minute spay?
00:37:24
Ryan Bailey
And hypotension.
00:37:28
Ryan Bailey
Oh, for sure. For sure.
00:37:32
vetgb89
No, it doesn't.
00:37:33
Ryan Bailey
Right.
00:37:33
Annatasha
It's probably gonna make everything better.
00:37:33
Ryan Bailey
You got to spend more time solving this event than like, actually,
00:37:34
vetgb89
It doesn't matter.
00:37:36
Annatasha
It's probably gonna make, a I mean, I don't vent from the get-go on every case.
00:37:40
Ryan Bailey
Yeah, yeah, for sure. Oh, I barely once at all. Like I just it's out of laziness,
Understanding Ventilators in Veterinary Practice
00:37:44
Ryan Bailey
honestly.
00:37:44
Annatasha
Well, I barely vent at all, because I try to you know keep isoflurin at an expired fraction of basically like 0.8.
00:37:45
Ryan Bailey
I'm just like.
00:37:50
Annatasha
That's my goal.
00:37:51
Ryan Bailey
Yeah.
00:37:52
Annatasha
I'm like, let's get this bad boy down below one.
00:37:52
Ryan Bailey
Yeah.
00:37:54
Annatasha
Let's do this, people.
00:37:57
vetgb89
see I mean, to be honest, though right if if if more people were to understand like how actually to actually use a ventilator, it would make their life much easier. right There is a lot of practitioners out there that are really worried about it. Actually, if you know how to use the tool, it makes your life so much easier. right how many How many patients suffer complications because they don't breathe for them, right?
00:38:25
vetgb89
They forget about it. Or while they're scrubbing, you know, they're busy doing other stuff and then, you know, the patient is happening, it can, you know, it becomes hypoxynic, right?
00:38:36
vetgb89
Or, you know, how many patients actually do wake up because they don't breathe for them at the beginning of anesthesia, right?
00:38:44
Annatasha
you People forget that like when the patient is apnic, likely from induction of anesthesia, that no breathing, no isoflurane, no isoflurane, no anesthesia.
00:38:54
Annatasha
right so it's like They'll be like, oh um don't need to turn up the ISO or I don't need to intervene because the patient's not breathing, which means it's too deep.
00:38:55
vetgb89
Right.
00:39:01
Annatasha
and It's like, no, that's not the same thing. like You can be just apnic and not be at an appropriate plane, but if you're not actually ventilating, You're not getting any uptake. Same thing in recovery. You're not getting any like egress of the inhalant and it's like, obviously it's going to wake up or obviously it's not going to wake up because you need to move the isophorane. So yeah.
00:39:22
vetgb89
yeah Yeah, I think there is a lack of understanding on like how actually, again, you know, the whole is a foreign thing or in England's work, right? Like, you know, you can do not the vaporizer fill up your circle, but if the patient doesn't breathe, it's not going to dig in. Right. So.
00:39:38
Annatasha
I mean, I don't, I don't blame them, right? Like if you think about like, even now that school, you get two weeks on anesthesia, if you're lucky, which is really 10 business days, and you're supposed to learn everything that we know from like three or more years in 10 business days, and then you get out into a system where you don't have the supplies and you you know, you're limited in your drug usage.
00:39:45
vetgb89
Yeah.
00:39:49
vetgb89
yeah
00:39:56
Annatasha
And so yeah, I kind of I do get it.
00:39:59
vetgb89
yeah
00:40:00
Annatasha
I get it.
00:40:00
Ryan Bailey
Yeah.
00:40:01
Annatasha
But at the same time, I'm like, it's okay to try to be better.
Gas Anesthesia Uptake
00:40:04
Annatasha
And there's
00:40:04
Ryan Bailey
And the physics of like, the physics of circle systems are like, they're not easy to understand.
00:40:05
vetgb89
yeah
00:40:10
Ryan Bailey
Like the physics of gas anesthesia uptake is not, it is not simple. Like it's not simple at all.
00:40:18
vetgb89
All right, now let's check.
00:40:18
Annatasha
Which brings me back to our oral exam, which was, one of my questions was like the difference between the vaporizer and the end title, right? And so basically like my end, at my, you know, end expired isoflurine value was higher than what the vaporizer was dialed, higher. And so you had to talk through how to troubleshoot that.
00:40:40
Annatasha
That was my whole oral question. And I was like, oh, just gonna swallow glass. Like just what a nightmare that was. But yeah, no, like, ah I mean, it's not easy, like gas analysis, uptake and all that kind of stuff.
00:40:51
Annatasha
And you have to like, I had to be like, are we at high altitude, are we at low altitude? Like what's, you know, like it's ridiculously.
00:40:55
Ryan Bailey
Is the vaporizer filled?
00:40:58
Annatasha
before I asked that, was it filled with the right agent? you know like i But yeah, no, that was that was my back to the oral exam.
00:41:01
Ryan Bailey
Yeah? Is it breathing nothing?
00:41:07
Annatasha
It was totally about gas you know gas uptake. And do I understand how gas analysis works?
Fluid Bolus in Cats vs Dogs
00:41:12
Annatasha
And it was a real nightmare of a question. o
00:41:16
vetgb89
Yeah, I will. I will not wonder that question. Definitely.
00:41:20
Annatasha
Yeah, no, I definitely sweat in some uncomfortable places, gentlemen.
00:41:20
vetgb89
You know.
00:41:28
vetgb89
awesome awesome So think the recap for for everybody, fluid bolus is fine if your patient is dehydrated. Otherwise, I mean, it's probably one of the least dangerous options that you have and also probably the least effective of your options is 100% true.
00:41:45
Annatasha
effective. Sorry.
00:41:56
Ryan Bailey
Do you feel like cats are lower likely?
00:41:57
vetgb89
Yeah.
00:41:59
Ryan Bailey
Like I personally just like subjectively and I have no evidence to back this up. So like, this is all just wild speculation for me.
00:42:06
Annatasha
This is my favorite kind from you, Bailey. It's when there's no evidence whatsoever.
00:42:09
Ryan Bailey
you
00:42:10
Annatasha
And it's your wild speculation.
00:42:11
Ryan Bailey
No, no, it's not just, I've been doing this.
00:42:12
Annatasha
So lay it on us.
00:42:15
Annatasha
is this your sympathetic thing about cat
00:42:15
Ryan Bailey
I've been doing it.
00:42:17
Annatasha
cats and
00:42:18
Ryan Bailey
It's not and not going there.
00:42:20
Ryan Bailey
Not yet. Not yet. I mean, I've been doing anesthesia for 10 years now. It's wild.
00:42:26
vetgb89
You're so old.
00:42:26
Ryan Bailey
But, I know, do you think that cats are less likely to respond to fluid boluses than dogs?
00:42:38
Annatasha
Is this your sympathetic thing about cats?
00:42:39
vetgb89
o
00:42:40
Ryan Bailey
Right, see, dogs are responders and cats are just not.
00:42:41
vetgb89
i I don't know, man.
00:42:47
Annatasha
Yeah.
00:42:48
vetgb89
I mean...
00:42:48
Annatasha
Now here's a question. Let's put it into some context. Do you think it's because your fluid resuscitation protocols are more judicious in cats? So do you give less volume and more slowly?
00:42:59
Annatasha
Because if you're really, cause you're like, you know, you can hammer fluids into a Labrador and right.
00:43:03
Ryan Bailey
He is fast to me always. Like it is as fast as the pump will let me go is as fast as gravity allows it to drift through the catheter. It is as fast as I can push a syringe.
00:43:10
Annatasha
OK, OK.
00:43:12
Ryan Bailey
and
00:43:12
Annatasha
Some people, you know, they're like, oh, I'll give two mils for cake over the next five years. And you're like, well, why bother?
00:43:17
Ryan Bailey
No.
00:43:18
Annatasha
But I just didn't know if you maybe your your fluid approach to cats was more judicious. So it was inherently biasing you. But that's fine.
00:43:25
Ryan Bailey
The volume is lower. Like I do give cats a five mil per kilo bolus based on like the idea that cats blood volume is 60 relative to a dog's blood volume of 90. So I do, I do give them less. So like, yes, that is a, that is an interesting point. Like to me giving 20 mils per kilo to a cat seems like.
00:43:42
Annatasha
And has anyone ever studied to see whether or not a cat actually has a proper Bainbridge reflex like pigs and people and dogs and non-human primates do? Because I don't think they have. So maybe they don't have that kick up for like atrial stretch does not initiate attack a tachycardic reflex.
00:43:58
Ryan Bailey
Yeah.
00:43:59
vetgb89
Yeah, that's fair.
00:44:00
Annatasha
This is my wild speculation in response to your wild speculation, which brings me back to the whole theme of fancy
00:44:00
vetgb89
Fair point.
00:44:03
Ryan Bailey
Nope.
00:44:05
Annatasha
But anyway, yeah, no, i I mean, let me put it this way. There's not a lot the cats respond to. my My general go-to for a cat is a fedron.
00:44:11
Ryan Bailey
Nope.
00:44:17
Ryan Bailey
Yeah.
00:44:18
vetgb89
Wow.
00:44:18
Ryan Bailey
Diminishing it.
00:44:20
Annatasha
Yeah. I like a Fedron and a cat. it's it's I find it more predictable. I get good duration. I don't tend to get like crazy tacky arrhythmias with it.
00:44:32
Annatasha
I don't have to set up a CRI, which is great because I'm inherently lazy, so that's super, but yeah.
00:44:33
vetgb89
Interesting.
00:44:39
vetgb89
Well, those are the values that you normally use.
00:44:42
Annatasha
0.1 megs per gig.
00:44:45
vetgb89
Okay. Okay.
00:44:45
Ryan Bailey
How often?
00:44:46
Annatasha
About maybe 30 minutes.
00:44:49
Ryan Bailey
And how many times?
00:44:51
Annatasha
Well, until it stops working, until you hit the wall of tactical axis.
00:44:55
Ryan Bailey
Right, that's what I was wondering, like how long?
00:44:56
Annatasha
But I've never hit it, right? Like I've never, cause I'm not just sitting there. Let me, let me be clear to our three listeners. I'm not just sitting there doing nothing but slamming in a fidget.
00:45:04
Ryan Bailey
No, I, I just, I've not used ephedrine cause like we don't have it where I work. I have seen it used in some practices, but just don't have the,
00:45:13
Annatasha
It's not as great in dogs. It maybe buys you five minutes of a burst in a dog and then it just wanes.
00:45:17
Ryan Bailey
yeah
00:45:18
Annatasha
But I've never had the tachyphylactic sealing in my patients because I'm doing other things like trying to turn my ISO down and titrating CRI's and warming them up and telling the surgeon to fenuria.
00:45:21
Ryan Bailey
Yeah. Okay. Right, right, right.
00:45:31
Ryan Bailey
Yeah.
00:45:31
Annatasha
stop talking with your hands in the air and put them back in the abdomen type thing.
00:45:34
Annatasha
So, yeah, I, I have never had that tacky philactic, but I did once allow a technician who was doing BTS training to run an ephedrine CRI. And I think we probably were, yeah, yeah, it's doable, but you just can't do it for hours and hours.
00:45:46
vetgb89
wild
00:45:51
Annatasha
So we had it on for maybe like 40 minutes and and it was efficacious. But I think if we'd pushed it much past that, but again, I have no idea. Cause that fancy guessing, like, I don't know what your endogenous levels of noradrenaline are.
00:46:02
Annatasha
So, and I don't know how much got used putting the catheter in. So it's impossible to say, but yeah, a Fedrons my go-to in cats.
00:46:11
vetgb89
Wow, okay.
00:46:11
Annatasha
Just mix it up, mix it up, mix it up.
00:46:12
vetgb89
It's, I mean, it's kind of hard to get to Fedron in the States, like depending on, you know, which state you're in, but like almost every state is trying to crack down on, you know, the use of a Fedron around.
00:46:13
Annatasha
I mean,
00:46:31
vetgb89
Well, yeah, you can,
00:46:32
Annatasha
i mean I get, I get why, but, like, cause I have no problems getting it up here in the wilds of Canada.
00:46:39
vetgb89
Yeah. Like every single time you go get Sudafed, which is like sell a figure and you need to give them your driver license and all that stuff, right? So like, you know, think about having the injectable version, which is even more pure.
00:46:51
vetgb89
yeah i'm saying
00:46:53
Annatasha
Whereas up here in Canada, like you can just walk over the counter. I mean, I'm not even, you know, and I'm not gonna make the gun control joke.
00:47:06
vetgb89
I mean, at least you have Kinder eggs, right?
00:47:09
Annatasha
But yeah, I'm sorry, I didn't realize there was an issue with availability, but yeah.
00:47:15
vetgb89
Yeah, it's it's hard to come by.
00:47:15
Annatasha
Yeah, it's less fluid responsive. You know, Bailey, I've never really identified that pattern, but I've also not been looking for it. But now that you've said it, I'm going to spend like the next three weeks just staring at every cat.
00:47:25
vetgb89
Yeah.
00:47:28
Ryan Bailey
i mean i'm a like
00:47:28
vetgb89
Me too.
00:47:30
Ryan Bailey
like i am a like Most of my patients, I would say 90% of my patients, if they are hypotensive and I think we can we've already turned down the gas, like step one is going to be some amount of fluids to see if they respond, to like gauge their response with the idea of like maximizing the diastolic filling as best I can because we don't have ways to measure it easily in my patients.
00:47:51
Ryan Bailey
And I believe most of my patients are going to fall in that, like, nice part of the bell curve where I'm not going to overload them. And I'm making very conscious decisions about these patients because I, you know, have a population where I can really monitor them closely. um um And so, like, I feel I don't see cats respond as quickly. And dogs, I feel like I get a lot of response.
00:48:14
Annatasha
Okay.
00:48:15
vetgb89
It's fair.
00:48:15
Annatasha
Interesting.
00:48:15
Ryan Bailey
cay of her
00:48:16
vetgb89
I'll keep an eye out for it for sure now.
00:48:17
Ryan Bailey
Yep.
00:48:20
Ryan Bailey
yeah
00:48:20
Annatasha
Do you guys always check before you start like, ah ah and like intervening with fluid therapy? Do you look though for like pulse pressure variations? Cause what I sometimes do is like, I'll just bag the patient if I'm not ventilating them, right?
00:48:32
Annatasha
I'll give them a few positive pressure breaths and then I'll see if I get a big response and then make make the decision volume.
00:48:37
Ryan Bailey
I mean, knowing how, knowing how subjective that is, and then with the like kind of lower crystalloid rates, we run them at in modern anesthesia, I feel pretty comfortable giving them like at least one bolus before I decide to like, alternate other therapies with them.
00:48:54
Annatasha
Well, yeah, you know, I won't check it before one bolus, but let's say, you know, we're, we're climbing up to the, you know, we're still tachycardic and hypotensive.
00:49:01
Ryan Bailey
For sure.
00:49:02
Annatasha
And then I'll be like, you know what, let's just see if there is really volume deplete. And then also I'm monitoring to see whether or not you're responding. Cause if you're not responding, even though you're deplete, I'm just going to stop that you want a vasoconstrictor, right?
00:49:12
Ryan Bailey
Right. Exactly. Like that's exactly the the point is like, if you're not responding, why do you go back to that same? Well, like you've already exhausted that like you've done.
00:49:21
Annatasha
I think it's because people don't realize that there is like a curve, right?
00:49:27
Ryan Bailey
Yeah, for sure.
00:49:29
Annatasha
don't think that that's that is not something that is, I think, taught at school. i think that
00:49:34
vetgb89
Absolutely not.
00:49:35
Ryan Bailey
They're on the like, Like they're on the, they're already on the flat part of the Starling curve, you know, like some days.
00:49:40
Annatasha
I was about to say, here we are again at Starling. like
00:49:43
vetgb89
There you go.
00:49:44
Ryan Bailey
Yeah.
00:49:44
Annatasha
We are going to starling.
Responses to Hypovolemia
00:49:46
Annatasha
yeah, no, I think just because you are hypovolemic does not mean you are going to normalize blood pressure with volume resuscitation.
00:49:54
Annatasha
And I, you know, and and I don't think that's something that is well known within the general community.
00:49:55
vetgb89
yeah
00:50:01
Annatasha
So, I think some of the physiologists don't know that.
00:50:02
Ryan Bailey
Yeah.
00:50:03
vetgb89
Yeah. No, that's, that's fair.
00:50:08
vetgb89
Probably.
00:50:10
Annatasha
So.
00:50:10
vetgb89
That's, that's probably true. I actually, you know, coming back to your point of like tachycardia and so if my patient is not tachycardic,
00:50:21
vetgb89
I usually look at the CVTP, and if it's not abnormal, then I skip the flipboards and they're completely like, I'm gonna give one period zero. If you, again, going back to the not wasting time on stuff, that doesn't work. And then, I mean, if that's not the issue, that's not the issue period, like, right? You know what I mean?
00:50:49
vetgb89
but if If it is telecardic, I usually actually do a mini fluid challenge. I just give three ml per cake, real fast, slam it in, and look for that drop in heart rate.
00:51:04
vetgb89
right and if And if it does drop like 10 points or more, then there you go.
00:51:05
Ryan Bailey
Yeah.
00:51:08
Ryan Bailey
Yep.
00:51:10
vetgb89
That's a good response of patient. but But yeah, I guess I never...
00:51:16
vetgb89
Yeah, I mean, I looked at post-pressure variation if it's a ray modendalator. I guess I, I don't know, out of laziness probably, I never actually did beg a patient to try to trigger post-pressure variation. But yeah, I'll start doing that more actually, that's pretty cool.
00:51:35
Annatasha
So what are your guys' thoughts on like this concept of the relative hypovolemia that we may or may not induce from eatrogenic vasodilation? So layman's terms, like we put them on vasodilators, and then the volume becomes relatively hypovolemic to the actual volume of the vascular tree. that that That theory used to be really common, but it's kind of on the fence now as to whether or not it has merit.
00:52:04
Ryan Bailey
I mean, but no, you go.
00:52:04
vetgb89
Yeah, i sorry, go for it. No, no, you go.
00:52:10
Ryan Bailey
Okay. I mean, I'm, I definitely am. going to be in the camp that's like you in in your normal, healthy patients who are not dealing with like multiple comorbidities or significant underlying disease that's requiring surgery.
00:52:29
Annatasha
Cause it used to be like the thing was like you wanted to fill up the well, right? So like you expanded vascular volume. You wanted to fill up the well with, with the volume deficit to stabilize blood pressure, but
00:52:41
vetgb89
Yeah.
00:52:43
Annatasha
yeah Okay, beanie.
00:52:44
vetgb89
Yeah. No, that's, to be honest with you, if the tissue is vasovallation, fix the vasovallation, right? Like give Norebi. If that's your worry, like the vasovallation and the decrease is going to accrete you from the isa, Norebi naturally is your key. Now, if the tissue has alpha,
00:53:07
vetgb89
give an anticoinergic. If your tissue has dehydration, give fluids.
00:53:14
vetgb89
If your issue is the patient is too deep, then, you know, maybe lighter. But if those three are not the problem, then norepinephrine surrounds her in probably 95% of the patients, bearing, you know, amount of obesity or GCN.
00:53:31
Annatasha
i He mean just made anesthesia sound so easy, eh? He's just like, yeah, just do this. Just do this.
00:53:36
vetgb89
No, I mean, it's it's not, but like, you know, I
00:53:39
Annatasha
No, I think the issue as well is, is you know like which one is it? and And then relative degrees of it. like Maybe it's 5% dehydration and 19% hypothermia and whatever percent. And the thing is, is that we're used to it. So it's like, yeah.
00:53:55
Annatasha
But in GP, they're like, I don't know if this patient is hypovolemic or I don't know if this patient is, you know, and they get in a fluster because it's multifactorial. But you didn't make that sound really easy. you' Like, oh, if it's hypovolemic, give it volume. If it's heart rate is low, give it an anti-coloninear attack.
00:54:10
vetgb89
No, it's not. It's not. But, you know, I don't know. I think that's how I think in my head. But yeah, of course, there's different shades of, you know, hypotension, I guess.
00:54:27
Annatasha
Yeah. Yeah. And there's some days where you're like, that's, you know, the textbook reads, you know, like it, you'll see like maybe lactate is 5.6 and basic success is minus 11 and the patient has weak peripheral pulses and it's, you know,
00:54:29
vetgb89
Anyway.
00:54:43
Annatasha
PCV is 61, you know, like all the signs are there, like it's pulse pressure variation is 17%, you know, and, you know, like you said, and you follow the textbook, right, like you normalize heart rate, and you lower the ISO, and you give, you know, a presser and a bolus, and they still stay hypotensive, right?
00:54:57
Annatasha
And you're like, why is this happening?
00:54:59
vetgb89
and
00:55:01
Annatasha
like did And like it's never in the patient that you expect it in, too. right like It'll be in some two-year-old TPLO lab, and you'll spend the whole anesthesia battling this dog from the brink of death for no apparent reason.
Unexpected Patient Behaviors and Episode Wrap-Up
00:55:13
Annatasha
And meanwhile, like the 18-year-old cat getting its O2 because it's in renal failure just like cruises anesthesia like nobody's business. And you're like, I'm definitely losing at the game today.
00:55:23
vetgb89
You know? And so it's going to be the exception out there.
00:55:27
Annatasha
Well done.
00:55:27
vetgb89
You know what I mean?
00:55:29
vetgb89
there was a You're fine. I can cut that off.
00:55:35
Annatasha
I was like, wow, I'm deaf.
00:55:38
vetgb89
I'll be sending you the bill for the hearing aid.
00:55:42
Annatasha
I was like, oh, I must've been the corn.
00:55:51
Annatasha
Hey, hilarious.
00:55:52
vetgb89
All right. I think we're coming up on the hour. um thank you so much for being here. Thank you so much for all your answers and extra questions that now we have. And I guess we'll see you in the next episode.
00:56:14
Annatasha
Yeah, I can't wait. I can't wait to decide what we're going to catastrophize next time.
00:56:17
vetgb89
who who's gonna Who wants to pick the next topic? Ryan or Tasha?
00:56:24
Annatasha
I think we should go alphabetically and Bailey comes before Bartel.
00:56:29
vetgb89
ah ah Okay, okay, that's fair.
00:56:30
Annatasha
But I'm happy to give today's summary, which is we don't understand fluids and we don't understand isoflurian and we don't understand cats. and Yeah, we don't understand circuits, and we're the experts, so that's super comforting.
00:56:45
vetgb89
Yeah. yeah
00:56:46
Annatasha
I hope Peter Pascoe never listens to this.
00:56:53
Annatasha
He'll just be so mortified that he trained any of us.
00:56:55
vetgb89
the
00:56:57
Annatasha
like He'll just be like, those three just need to get voted off the island.
00:57:00
vetgb89
At some point your phone's gonna ring and Peter's gonna be on the other side of the line.
00:57:01
Annatasha
yes
00:57:05
Annatasha
Oh God, it's going to be pee, pee, pee. And like, I'm just going to, oh, the sweating is going to start again.
00:57:11
vetgb89
I may or may not shoot him a link.
00:57:14
Annatasha
Don't you dare. Don't you dare. Don't you dare. No, this length only goes to very specific anesthesiologists.